1. Field of the Invention
The present invention relates to a lighting module, and particularly relates to a lighting module with a heat-dissipation structure that is easy to assemble.
2. Background of the Invention
Electronic products are becoming increasingly lightweight and small. FIG. 1 illustrates a secure structure designed for a conventional flashlight that dissipates heat. A flashlight 1a has a cavity 11a formed inside for receiving a battery device 12a. The flashlight 1a includes conductive structures 13a and 14a arranged in a front portion and a rear portion thereof in order to sandwich and electrically connect the battery device 12a. A lighting unit 15a of the flashlight 1a connects to the conductive structure 13a so as to irradiate thereby. Due to the heat created by the irradiation of the lighting unit 15a, damage may occur to the device affecting the product's service life. An aluminum sleeve 2a is disposed to retain against the conductive structures 13a for transferring heat. In addition, to secure the lighting unit 15a in the flashlight 1a, an aluminum ring 21a with exterior screw threads is abutted against the conductive structures 13a to secure the conductive structures 13a inside the flashlight 1a. The conventional secure structure mentioned above suffers from having many complicated steps for assembling the flashlight 1a. The aluminum ring 21a should be arranged inside the flashlight 1a first to orientate the conductive structures 13a, the aluminum sleeve 2a, for heat dissipation, is then inserted, and the other components of the flashlight 1a are assembled sequentially. Furthermore, the conductive structure 13a, made from a polypropylene plate 132a, (so called PP plate) is sandwiched by two metallic plates 131 and 133a. The lighting unit 15a contacts the metallic plates 133a directly. The metallic plate 133a has a peripheral portion folding downwardly to cover and contact the opposite metallic plate 131a to dissipate the heat outwardly. The contact portions between the two metallic plates 131 and 133a are restrained by the peripheral portion and screws 134a that penetrate therethrough. After the aluminum ring 21a is positioned to contact the metallic plate 133a, another contact area therebetween is formed in an annular shape on the aluminum sleeve 2a. The heat dissipation efficiency is restrained by the contact portion between the two metallic plates 131 and 133a and the contact area between the aluminum ring 21a and the metallic plate 133a. Due to the nature of the design it is difficult to be improved thereby. In addition, the structure formed by the metallic plate 133a and the aluminum ring 21a, and between the aluminum ring 21a and the aluminum sleeve 2a, must be taken into consideration. Obviously, this structure has at least two heat chokes. The first occurs between the two metallic plates 131 and 133a, and the other occurs between the aluminum ring 21a and the metallic plate 133a. 